linux/drivers/hwmon/acpi_power_meter.c
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   1/*
   2 * A hwmon driver for ACPI 4.0 power meters
   3 * Copyright (C) 2009 IBM
   4 *
   5 * Author: Darrick J. Wong <djwong@us.ibm.com>
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License as published by
   9 * the Free Software Foundation; either version 2 of the License, or
  10 * (at your option) any later version.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program; if not, write to the Free Software
  19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20 */
  21
  22#include <linux/module.h>
  23#include <linux/hwmon.h>
  24#include <linux/hwmon-sysfs.h>
  25#include <linux/jiffies.h>
  26#include <linux/mutex.h>
  27#include <linux/dmi.h>
  28#include <linux/slab.h>
  29#include <linux/kdev_t.h>
  30#include <linux/sched.h>
  31#include <linux/time.h>
  32#include <acpi/acpi_drivers.h>
  33#include <acpi/acpi_bus.h>
  34
  35#define ACPI_POWER_METER_NAME           "power_meter"
  36ACPI_MODULE_NAME(ACPI_POWER_METER_NAME);
  37#define ACPI_POWER_METER_DEVICE_NAME    "Power Meter"
  38#define ACPI_POWER_METER_CLASS          "pwr_meter_resource"
  39
  40#define NUM_SENSORS                     17
  41
  42#define POWER_METER_CAN_MEASURE (1 << 0)
  43#define POWER_METER_CAN_TRIP    (1 << 1)
  44#define POWER_METER_CAN_CAP     (1 << 2)
  45#define POWER_METER_CAN_NOTIFY  (1 << 3)
  46#define POWER_METER_IS_BATTERY  (1 << 8)
  47#define UNKNOWN_HYSTERESIS      0xFFFFFFFF
  48
  49#define METER_NOTIFY_CONFIG     0x80
  50#define METER_NOTIFY_TRIP       0x81
  51#define METER_NOTIFY_CAP        0x82
  52#define METER_NOTIFY_CAPPING    0x83
  53#define METER_NOTIFY_INTERVAL   0x84
  54
  55#define POWER_AVERAGE_NAME      "power1_average"
  56#define POWER_CAP_NAME          "power1_cap"
  57#define POWER_AVG_INTERVAL_NAME "power1_average_interval"
  58#define POWER_ALARM_NAME        "power1_alarm"
  59
  60static int cap_in_hardware;
  61static bool force_cap_on;
  62
  63static int can_cap_in_hardware(void)
  64{
  65        return force_cap_on || cap_in_hardware;
  66}
  67
  68static const struct acpi_device_id power_meter_ids[] = {
  69        {"ACPI000D", 0},
  70        {"", 0},
  71};
  72MODULE_DEVICE_TABLE(acpi, power_meter_ids);
  73
  74struct acpi_power_meter_capabilities {
  75        u64             flags;
  76        u64             units;
  77        u64             type;
  78        u64             accuracy;
  79        u64             sampling_time;
  80        u64             min_avg_interval;
  81        u64             max_avg_interval;
  82        u64             hysteresis;
  83        u64             configurable_cap;
  84        u64             min_cap;
  85        u64             max_cap;
  86};
  87
  88struct acpi_power_meter_resource {
  89        struct acpi_device      *acpi_dev;
  90        acpi_bus_id             name;
  91        struct mutex            lock;
  92        struct device           *hwmon_dev;
  93        struct acpi_power_meter_capabilities    caps;
  94        acpi_string             model_number;
  95        acpi_string             serial_number;
  96        acpi_string             oem_info;
  97        u64             power;
  98        u64             cap;
  99        u64             avg_interval;
 100        int                     sensors_valid;
 101        unsigned long           sensors_last_updated;
 102        struct sensor_device_attribute  sensors[NUM_SENSORS];
 103        int                     num_sensors;
 104        s64                     trip[2];
 105        int                     num_domain_devices;
 106        struct acpi_device      **domain_devices;
 107        struct kobject          *holders_dir;
 108};
 109
 110struct sensor_template {
 111        char *label;
 112        ssize_t (*show)(struct device *dev,
 113                        struct device_attribute *devattr,
 114                        char *buf);
 115        ssize_t (*set)(struct device *dev,
 116                       struct device_attribute *devattr,
 117                       const char *buf, size_t count);
 118        int index;
 119};
 120
 121/* Averaging interval */
 122static int update_avg_interval(struct acpi_power_meter_resource *resource)
 123{
 124        unsigned long long data;
 125        acpi_status status;
 126
 127        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GAI",
 128                                       NULL, &data);
 129        if (ACPI_FAILURE(status)) {
 130                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GAI"));
 131                return -ENODEV;
 132        }
 133
 134        resource->avg_interval = data;
 135        return 0;
 136}
 137
 138static ssize_t show_avg_interval(struct device *dev,
 139                                 struct device_attribute *devattr,
 140                                 char *buf)
 141{
 142        struct acpi_device *acpi_dev = to_acpi_device(dev);
 143        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 144
 145        mutex_lock(&resource->lock);
 146        update_avg_interval(resource);
 147        mutex_unlock(&resource->lock);
 148
 149        return sprintf(buf, "%llu\n", resource->avg_interval);
 150}
 151
 152static ssize_t set_avg_interval(struct device *dev,
 153                                struct device_attribute *devattr,
 154                                const char *buf, size_t count)
 155{
 156        struct acpi_device *acpi_dev = to_acpi_device(dev);
 157        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 158        union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 159        struct acpi_object_list args = { 1, &arg0 };
 160        int res;
 161        unsigned long temp;
 162        unsigned long long data;
 163        acpi_status status;
 164
 165        res = kstrtoul(buf, 10, &temp);
 166        if (res)
 167                return res;
 168
 169        if (temp > resource->caps.max_avg_interval ||
 170            temp < resource->caps.min_avg_interval)
 171                return -EINVAL;
 172        arg0.integer.value = temp;
 173
 174        mutex_lock(&resource->lock);
 175        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PAI",
 176                                       &args, &data);
 177        if (!ACPI_FAILURE(status))
 178                resource->avg_interval = temp;
 179        mutex_unlock(&resource->lock);
 180
 181        if (ACPI_FAILURE(status)) {
 182                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PAI"));
 183                return -EINVAL;
 184        }
 185
 186        /* _PAI returns 0 on success, nonzero otherwise */
 187        if (data)
 188                return -EINVAL;
 189
 190        return count;
 191}
 192
 193/* Cap functions */
 194static int update_cap(struct acpi_power_meter_resource *resource)
 195{
 196        unsigned long long data;
 197        acpi_status status;
 198
 199        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GHL",
 200                                       NULL, &data);
 201        if (ACPI_FAILURE(status)) {
 202                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GHL"));
 203                return -ENODEV;
 204        }
 205
 206        resource->cap = data;
 207        return 0;
 208}
 209
 210static ssize_t show_cap(struct device *dev,
 211                        struct device_attribute *devattr,
 212                        char *buf)
 213{
 214        struct acpi_device *acpi_dev = to_acpi_device(dev);
 215        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 216
 217        mutex_lock(&resource->lock);
 218        update_cap(resource);
 219        mutex_unlock(&resource->lock);
 220
 221        return sprintf(buf, "%llu\n", resource->cap * 1000);
 222}
 223
 224static ssize_t set_cap(struct device *dev, struct device_attribute *devattr,
 225                       const char *buf, size_t count)
 226{
 227        struct acpi_device *acpi_dev = to_acpi_device(dev);
 228        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 229        union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 230        struct acpi_object_list args = { 1, &arg0 };
 231        int res;
 232        unsigned long temp;
 233        unsigned long long data;
 234        acpi_status status;
 235
 236        res = kstrtoul(buf, 10, &temp);
 237        if (res)
 238                return res;
 239
 240        temp = DIV_ROUND_CLOSEST(temp, 1000);
 241        if (temp > resource->caps.max_cap || temp < resource->caps.min_cap)
 242                return -EINVAL;
 243        arg0.integer.value = temp;
 244
 245        mutex_lock(&resource->lock);
 246        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_SHL",
 247                                       &args, &data);
 248        if (!ACPI_FAILURE(status))
 249                resource->cap = temp;
 250        mutex_unlock(&resource->lock);
 251
 252        if (ACPI_FAILURE(status)) {
 253                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SHL"));
 254                return -EINVAL;
 255        }
 256
 257        /* _SHL returns 0 on success, nonzero otherwise */
 258        if (data)
 259                return -EINVAL;
 260
 261        return count;
 262}
 263
 264/* Power meter trip points */
 265static int set_acpi_trip(struct acpi_power_meter_resource *resource)
 266{
 267        union acpi_object arg_objs[] = {
 268                {ACPI_TYPE_INTEGER},
 269                {ACPI_TYPE_INTEGER}
 270        };
 271        struct acpi_object_list args = { 2, arg_objs };
 272        unsigned long long data;
 273        acpi_status status;
 274
 275        /* Both trip levels must be set */
 276        if (resource->trip[0] < 0 || resource->trip[1] < 0)
 277                return 0;
 278
 279        /* This driver stores min, max; ACPI wants max, min. */
 280        arg_objs[0].integer.value = resource->trip[1];
 281        arg_objs[1].integer.value = resource->trip[0];
 282
 283        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PTP",
 284                                       &args, &data);
 285        if (ACPI_FAILURE(status)) {
 286                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTP"));
 287                return -EINVAL;
 288        }
 289
 290        /* _PTP returns 0 on success, nonzero otherwise */
 291        if (data)
 292                return -EINVAL;
 293
 294        return 0;
 295}
 296
 297static ssize_t set_trip(struct device *dev, struct device_attribute *devattr,
 298                        const char *buf, size_t count)
 299{
 300        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 301        struct acpi_device *acpi_dev = to_acpi_device(dev);
 302        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 303        int res;
 304        unsigned long temp;
 305
 306        res = kstrtoul(buf, 10, &temp);
 307        if (res)
 308                return res;
 309
 310        temp = DIV_ROUND_CLOSEST(temp, 1000);
 311
 312        mutex_lock(&resource->lock);
 313        resource->trip[attr->index - 7] = temp;
 314        res = set_acpi_trip(resource);
 315        mutex_unlock(&resource->lock);
 316
 317        if (res)
 318                return res;
 319
 320        return count;
 321}
 322
 323/* Power meter */
 324static int update_meter(struct acpi_power_meter_resource *resource)
 325{
 326        unsigned long long data;
 327        acpi_status status;
 328        unsigned long local_jiffies = jiffies;
 329
 330        if (time_before(local_jiffies, resource->sensors_last_updated +
 331                        msecs_to_jiffies(resource->caps.sampling_time)) &&
 332                        resource->sensors_valid)
 333                return 0;
 334
 335        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM",
 336                                       NULL, &data);
 337        if (ACPI_FAILURE(status)) {
 338                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMM"));
 339                return -ENODEV;
 340        }
 341
 342        resource->power = data;
 343        resource->sensors_valid = 1;
 344        resource->sensors_last_updated = jiffies;
 345        return 0;
 346}
 347
 348static ssize_t show_power(struct device *dev,
 349                          struct device_attribute *devattr,
 350                          char *buf)
 351{
 352        struct acpi_device *acpi_dev = to_acpi_device(dev);
 353        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 354
 355        mutex_lock(&resource->lock);
 356        update_meter(resource);
 357        mutex_unlock(&resource->lock);
 358
 359        return sprintf(buf, "%llu\n", resource->power * 1000);
 360}
 361
 362/* Miscellaneous */
 363static ssize_t show_str(struct device *dev,
 364                        struct device_attribute *devattr,
 365                        char *buf)
 366{
 367        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 368        struct acpi_device *acpi_dev = to_acpi_device(dev);
 369        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 370        acpi_string val;
 371
 372        switch (attr->index) {
 373        case 0:
 374                val = resource->model_number;
 375                break;
 376        case 1:
 377                val = resource->serial_number;
 378                break;
 379        case 2:
 380                val = resource->oem_info;
 381                break;
 382        default:
 383                BUG();
 384                val = "";
 385        }
 386
 387        return sprintf(buf, "%s\n", val);
 388}
 389
 390static ssize_t show_val(struct device *dev,
 391                        struct device_attribute *devattr,
 392                        char *buf)
 393{
 394        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 395        struct acpi_device *acpi_dev = to_acpi_device(dev);
 396        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 397        u64 val = 0;
 398
 399        switch (attr->index) {
 400        case 0:
 401                val = resource->caps.min_avg_interval;
 402                break;
 403        case 1:
 404                val = resource->caps.max_avg_interval;
 405                break;
 406        case 2:
 407                val = resource->caps.min_cap * 1000;
 408                break;
 409        case 3:
 410                val = resource->caps.max_cap * 1000;
 411                break;
 412        case 4:
 413                if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
 414                        return sprintf(buf, "unknown\n");
 415
 416                val = resource->caps.hysteresis * 1000;
 417                break;
 418        case 5:
 419                if (resource->caps.flags & POWER_METER_IS_BATTERY)
 420                        val = 1;
 421                else
 422                        val = 0;
 423                break;
 424        case 6:
 425                if (resource->power > resource->cap)
 426                        val = 1;
 427                else
 428                        val = 0;
 429                break;
 430        case 7:
 431        case 8:
 432                if (resource->trip[attr->index - 7] < 0)
 433                        return sprintf(buf, "unknown\n");
 434
 435                val = resource->trip[attr->index - 7] * 1000;
 436                break;
 437        default:
 438                BUG();
 439        }
 440
 441        return sprintf(buf, "%llu\n", val);
 442}
 443
 444static ssize_t show_accuracy(struct device *dev,
 445                             struct device_attribute *devattr,
 446                             char *buf)
 447{
 448        struct acpi_device *acpi_dev = to_acpi_device(dev);
 449        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 450        unsigned int acc = resource->caps.accuracy;
 451
 452        return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
 453}
 454
 455static ssize_t show_name(struct device *dev,
 456                         struct device_attribute *devattr,
 457                         char *buf)
 458{
 459        return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
 460}
 461
 462#define RO_SENSOR_TEMPLATE(_label, _show, _index)       \
 463        {                                               \
 464                .label = _label,                        \
 465                .show  = _show,                         \
 466                .index = _index,                        \
 467        }
 468
 469#define RW_SENSOR_TEMPLATE(_label, _show, _set, _index) \
 470        {                                               \
 471                .label = _label,                        \
 472                .show  = _show,                         \
 473                .set   = _set,                          \
 474                .index = _index,                        \
 475        }
 476
 477/* Sensor descriptions.  If you add a sensor, update NUM_SENSORS above! */
 478static struct sensor_template meter_attrs[] = {
 479        RO_SENSOR_TEMPLATE(POWER_AVERAGE_NAME, show_power, 0),
 480        RO_SENSOR_TEMPLATE("power1_accuracy", show_accuracy, 0),
 481        RO_SENSOR_TEMPLATE("power1_average_interval_min", show_val, 0),
 482        RO_SENSOR_TEMPLATE("power1_average_interval_max", show_val, 1),
 483        RO_SENSOR_TEMPLATE("power1_is_battery", show_val, 5),
 484        RW_SENSOR_TEMPLATE(POWER_AVG_INTERVAL_NAME, show_avg_interval,
 485                set_avg_interval, 0),
 486        {},
 487};
 488
 489static struct sensor_template misc_cap_attrs[] = {
 490        RO_SENSOR_TEMPLATE("power1_cap_min", show_val, 2),
 491        RO_SENSOR_TEMPLATE("power1_cap_max", show_val, 3),
 492        RO_SENSOR_TEMPLATE("power1_cap_hyst", show_val, 4),
 493        RO_SENSOR_TEMPLATE(POWER_ALARM_NAME, show_val, 6),
 494        {},
 495};
 496
 497static struct sensor_template ro_cap_attrs[] = {
 498        RO_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, 0),
 499        {},
 500};
 501
 502static struct sensor_template rw_cap_attrs[] = {
 503        RW_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, set_cap, 0),
 504        {},
 505};
 506
 507static struct sensor_template trip_attrs[] = {
 508        RW_SENSOR_TEMPLATE("power1_average_min", show_val, set_trip, 7),
 509        RW_SENSOR_TEMPLATE("power1_average_max", show_val, set_trip, 8),
 510        {},
 511};
 512
 513static struct sensor_template misc_attrs[] = {
 514        RO_SENSOR_TEMPLATE("name", show_name, 0),
 515        RO_SENSOR_TEMPLATE("power1_model_number", show_str, 0),
 516        RO_SENSOR_TEMPLATE("power1_oem_info", show_str, 2),
 517        RO_SENSOR_TEMPLATE("power1_serial_number", show_str, 1),
 518        {},
 519};
 520
 521#undef RO_SENSOR_TEMPLATE
 522#undef RW_SENSOR_TEMPLATE
 523
 524/* Read power domain data */
 525static void remove_domain_devices(struct acpi_power_meter_resource *resource)
 526{
 527        int i;
 528
 529        if (!resource->num_domain_devices)
 530                return;
 531
 532        for (i = 0; i < resource->num_domain_devices; i++) {
 533                struct acpi_device *obj = resource->domain_devices[i];
 534                if (!obj)
 535                        continue;
 536
 537                sysfs_remove_link(resource->holders_dir,
 538                                  kobject_name(&obj->dev.kobj));
 539                put_device(&obj->dev);
 540        }
 541
 542        kfree(resource->domain_devices);
 543        kobject_put(resource->holders_dir);
 544        resource->num_domain_devices = 0;
 545}
 546
 547static int read_domain_devices(struct acpi_power_meter_resource *resource)
 548{
 549        int res = 0;
 550        int i;
 551        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 552        union acpi_object *pss;
 553        acpi_status status;
 554
 555        status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
 556                                      &buffer);
 557        if (ACPI_FAILURE(status)) {
 558                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMD"));
 559                return -ENODEV;
 560        }
 561
 562        pss = buffer.pointer;
 563        if (!pss ||
 564            pss->type != ACPI_TYPE_PACKAGE) {
 565                dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 566                        "Invalid _PMD data\n");
 567                res = -EFAULT;
 568                goto end;
 569        }
 570
 571        if (!pss->package.count)
 572                goto end;
 573
 574        resource->domain_devices = kzalloc(sizeof(struct acpi_device *) *
 575                                           pss->package.count, GFP_KERNEL);
 576        if (!resource->domain_devices) {
 577                res = -ENOMEM;
 578                goto end;
 579        }
 580
 581        resource->holders_dir = kobject_create_and_add("measures",
 582                                        &resource->acpi_dev->dev.kobj);
 583        if (!resource->holders_dir) {
 584                res = -ENOMEM;
 585                goto exit_free;
 586        }
 587
 588        resource->num_domain_devices = pss->package.count;
 589
 590        for (i = 0; i < pss->package.count; i++) {
 591                struct acpi_device *obj;
 592                union acpi_object *element = &(pss->package.elements[i]);
 593
 594                /* Refuse non-references */
 595                if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
 596                        continue;
 597
 598                /* Create a symlink to domain objects */
 599                resource->domain_devices[i] = NULL;
 600                status = acpi_bus_get_device(element->reference.handle,
 601                                             &resource->domain_devices[i]);
 602                if (ACPI_FAILURE(status))
 603                        continue;
 604
 605                obj = resource->domain_devices[i];
 606                get_device(&obj->dev);
 607
 608                res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
 609                                      kobject_name(&obj->dev.kobj));
 610                if (res) {
 611                        put_device(&obj->dev);
 612                        resource->domain_devices[i] = NULL;
 613                }
 614        }
 615
 616        res = 0;
 617        goto end;
 618
 619exit_free:
 620        kfree(resource->domain_devices);
 621end:
 622        kfree(buffer.pointer);
 623        return res;
 624}
 625
 626/* Registration and deregistration */
 627static int register_attrs(struct acpi_power_meter_resource *resource,
 628                          struct sensor_template *attrs)
 629{
 630        struct device *dev = &resource->acpi_dev->dev;
 631        struct sensor_device_attribute *sensors =
 632                &resource->sensors[resource->num_sensors];
 633        int res = 0;
 634
 635        while (attrs->label) {
 636                sensors->dev_attr.attr.name = attrs->label;
 637                sensors->dev_attr.attr.mode = S_IRUGO;
 638                sensors->dev_attr.show = attrs->show;
 639                sensors->index = attrs->index;
 640
 641                if (attrs->set) {
 642                        sensors->dev_attr.attr.mode |= S_IWUSR;
 643                        sensors->dev_attr.store = attrs->set;
 644                }
 645
 646                sysfs_attr_init(&sensors->dev_attr.attr);
 647                res = device_create_file(dev, &sensors->dev_attr);
 648                if (res) {
 649                        sensors->dev_attr.attr.name = NULL;
 650                        goto error;
 651                }
 652                sensors++;
 653                resource->num_sensors++;
 654                attrs++;
 655        }
 656
 657error:
 658        return res;
 659}
 660
 661static void remove_attrs(struct acpi_power_meter_resource *resource)
 662{
 663        int i;
 664
 665        for (i = 0; i < resource->num_sensors; i++) {
 666                if (!resource->sensors[i].dev_attr.attr.name)
 667                        continue;
 668                device_remove_file(&resource->acpi_dev->dev,
 669                                   &resource->sensors[i].dev_attr);
 670        }
 671
 672        remove_domain_devices(resource);
 673
 674        resource->num_sensors = 0;
 675}
 676
 677static int setup_attrs(struct acpi_power_meter_resource *resource)
 678{
 679        int res = 0;
 680
 681        res = read_domain_devices(resource);
 682        if (res)
 683                return res;
 684
 685        if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
 686                res = register_attrs(resource, meter_attrs);
 687                if (res)
 688                        goto error;
 689        }
 690
 691        if (resource->caps.flags & POWER_METER_CAN_CAP) {
 692                if (!can_cap_in_hardware()) {
 693                        dev_err(&resource->acpi_dev->dev,
 694                                "Ignoring unsafe software power cap!\n");
 695                        goto skip_unsafe_cap;
 696                }
 697
 698                if (resource->caps.configurable_cap)
 699                        res = register_attrs(resource, rw_cap_attrs);
 700                else
 701                        res = register_attrs(resource, ro_cap_attrs);
 702
 703                if (res)
 704                        goto error;
 705
 706                res = register_attrs(resource, misc_cap_attrs);
 707                if (res)
 708                        goto error;
 709        }
 710
 711skip_unsafe_cap:
 712        if (resource->caps.flags & POWER_METER_CAN_TRIP) {
 713                res = register_attrs(resource, trip_attrs);
 714                if (res)
 715                        goto error;
 716        }
 717
 718        res = register_attrs(resource, misc_attrs);
 719        if (res)
 720                goto error;
 721
 722        return res;
 723error:
 724        remove_attrs(resource);
 725        return res;
 726}
 727
 728static void free_capabilities(struct acpi_power_meter_resource *resource)
 729{
 730        acpi_string *str;
 731        int i;
 732
 733        str = &resource->model_number;
 734        for (i = 0; i < 3; i++, str++)
 735                kfree(*str);
 736}
 737
 738static int read_capabilities(struct acpi_power_meter_resource *resource)
 739{
 740        int res = 0;
 741        int i;
 742        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 743        struct acpi_buffer state = { 0, NULL };
 744        struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
 745        union acpi_object *pss;
 746        acpi_string *str;
 747        acpi_status status;
 748
 749        status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
 750                                      &buffer);
 751        if (ACPI_FAILURE(status)) {
 752                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMC"));
 753                return -ENODEV;
 754        }
 755
 756        pss = buffer.pointer;
 757        if (!pss ||
 758            pss->type != ACPI_TYPE_PACKAGE ||
 759            pss->package.count != 14) {
 760                dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 761                        "Invalid _PMC data\n");
 762                res = -EFAULT;
 763                goto end;
 764        }
 765
 766        /* Grab all the integer data at once */
 767        state.length = sizeof(struct acpi_power_meter_capabilities);
 768        state.pointer = &resource->caps;
 769
 770        status = acpi_extract_package(pss, &format, &state);
 771        if (ACPI_FAILURE(status)) {
 772                ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
 773                res = -EFAULT;
 774                goto end;
 775        }
 776
 777        if (resource->caps.units) {
 778                dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 779                        "Unknown units %llu.\n",
 780                        resource->caps.units);
 781                res = -EINVAL;
 782                goto end;
 783        }
 784
 785        /* Grab the string data */
 786        str = &resource->model_number;
 787
 788        for (i = 11; i < 14; i++) {
 789                union acpi_object *element = &(pss->package.elements[i]);
 790
 791                if (element->type != ACPI_TYPE_STRING) {
 792                        res = -EINVAL;
 793                        goto error;
 794                }
 795
 796                *str = kzalloc(sizeof(u8) * (element->string.length + 1),
 797                               GFP_KERNEL);
 798                if (!*str) {
 799                        res = -ENOMEM;
 800                        goto error;
 801                }
 802
 803                strncpy(*str, element->string.pointer, element->string.length);
 804                str++;
 805        }
 806
 807        dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
 808        goto end;
 809error:
 810        str = &resource->model_number;
 811        for (i = 0; i < 3; i++, str++)
 812                kfree(*str);
 813end:
 814        kfree(buffer.pointer);
 815        return res;
 816}
 817
 818/* Handle ACPI event notifications */
 819static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
 820{
 821        struct acpi_power_meter_resource *resource;
 822        int res;
 823
 824        if (!device || !acpi_driver_data(device))
 825                return;
 826
 827        resource = acpi_driver_data(device);
 828
 829        mutex_lock(&resource->lock);
 830        switch (event) {
 831        case METER_NOTIFY_CONFIG:
 832                free_capabilities(resource);
 833                res = read_capabilities(resource);
 834                if (res)
 835                        break;
 836
 837                remove_attrs(resource);
 838                setup_attrs(resource);
 839                break;
 840        case METER_NOTIFY_TRIP:
 841                sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
 842                update_meter(resource);
 843                break;
 844        case METER_NOTIFY_CAP:
 845                sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
 846                update_cap(resource);
 847                break;
 848        case METER_NOTIFY_INTERVAL:
 849                sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
 850                update_avg_interval(resource);
 851                break;
 852        case METER_NOTIFY_CAPPING:
 853                sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
 854                dev_info(&device->dev, "Capping in progress.\n");
 855                break;
 856        default:
 857                BUG();
 858        }
 859        mutex_unlock(&resource->lock);
 860
 861        acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
 862                                        dev_name(&device->dev), event, 0);
 863}
 864
 865static int acpi_power_meter_add(struct acpi_device *device)
 866{
 867        int res;
 868        struct acpi_power_meter_resource *resource;
 869
 870        if (!device)
 871                return -EINVAL;
 872
 873        resource = kzalloc(sizeof(struct acpi_power_meter_resource),
 874                           GFP_KERNEL);
 875        if (!resource)
 876                return -ENOMEM;
 877
 878        resource->sensors_valid = 0;
 879        resource->acpi_dev = device;
 880        mutex_init(&resource->lock);
 881        strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
 882        strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
 883        device->driver_data = resource;
 884
 885        free_capabilities(resource);
 886        res = read_capabilities(resource);
 887        if (res)
 888                goto exit_free;
 889
 890        resource->trip[0] = resource->trip[1] = -1;
 891
 892        res = setup_attrs(resource);
 893        if (res)
 894                goto exit_free;
 895
 896        resource->hwmon_dev = hwmon_device_register(&device->dev);
 897        if (IS_ERR(resource->hwmon_dev)) {
 898                res = PTR_ERR(resource->hwmon_dev);
 899                goto exit_remove;
 900        }
 901
 902        res = 0;
 903        goto exit;
 904
 905exit_remove:
 906        remove_attrs(resource);
 907exit_free:
 908        kfree(resource);
 909exit:
 910        return res;
 911}
 912
 913static int acpi_power_meter_remove(struct acpi_device *device, int type)
 914{
 915        struct acpi_power_meter_resource *resource;
 916
 917        if (!device || !acpi_driver_data(device))
 918                return -EINVAL;
 919
 920        resource = acpi_driver_data(device);
 921        hwmon_device_unregister(resource->hwmon_dev);
 922
 923        free_capabilities(resource);
 924        remove_attrs(resource);
 925
 926        kfree(resource);
 927        return 0;
 928}
 929
 930#ifdef CONFIG_PM_SLEEP
 931
 932static int acpi_power_meter_resume(struct device *dev)
 933{
 934        struct acpi_power_meter_resource *resource;
 935
 936        if (!dev)
 937                return -EINVAL;
 938
 939        resource = acpi_driver_data(to_acpi_device(dev));
 940        if (!resource)
 941                return -EINVAL;
 942
 943        free_capabilities(resource);
 944        read_capabilities(resource);
 945
 946        return 0;
 947}
 948
 949#endif /* CONFIG_PM_SLEEP */
 950
 951static SIMPLE_DEV_PM_OPS(acpi_power_meter_pm, NULL, acpi_power_meter_resume);
 952
 953static struct acpi_driver acpi_power_meter_driver = {
 954        .name = "power_meter",
 955        .class = ACPI_POWER_METER_CLASS,
 956        .ids = power_meter_ids,
 957        .ops = {
 958                .add = acpi_power_meter_add,
 959                .remove = acpi_power_meter_remove,
 960                .notify = acpi_power_meter_notify,
 961                },
 962        .drv.pm = &acpi_power_meter_pm,
 963};
 964
 965/* Module init/exit routines */
 966static int __init enable_cap_knobs(const struct dmi_system_id *d)
 967{
 968        cap_in_hardware = 1;
 969        return 0;
 970}
 971
 972static struct dmi_system_id __initdata pm_dmi_table[] = {
 973        {
 974                enable_cap_knobs, "IBM Active Energy Manager",
 975                {
 976                        DMI_MATCH(DMI_SYS_VENDOR, "IBM")
 977                },
 978        },
 979        {}
 980};
 981
 982static int __init acpi_power_meter_init(void)
 983{
 984        int result;
 985
 986        if (acpi_disabled)
 987                return -ENODEV;
 988
 989        dmi_check_system(pm_dmi_table);
 990
 991        result = acpi_bus_register_driver(&acpi_power_meter_driver);
 992        if (result < 0)
 993                return -ENODEV;
 994
 995        return 0;
 996}
 997
 998static void __exit acpi_power_meter_exit(void)
 999{
1000        acpi_bus_unregister_driver(&acpi_power_meter_driver);
1001}
1002
1003MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
1004MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
1005MODULE_LICENSE("GPL");
1006
1007module_param(force_cap_on, bool, 0644);
1008MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1009
1010module_init(acpi_power_meter_init);
1011module_exit(acpi_power_meter_exit);
1012
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